The concept of planting new seed rows on the same ridges used during the previous crop season is steadily growing in popularity for a number of good reasons. While it is important in carrying out such ridge planting techniques that the stubble and trash residue from last season's crop be skimmed off the crest of the ridge in order to leave a narrow band or strip of clean soil in which the seed receiving trench can be formed, it is also important to be able to carefully control the disposition of the crop roots, soil and other materials as they are skimmed off the crest while the planter moves along. In some cases the farmer may want to keep the skimmed off materials as close as possible to the newly planted seed row, while at other times he may want to deposit the residue further away from the row. Depending upon the circumstances, he may wish to be able to vary this extent of lateral throw and yet maintain the same skimming depth so that the seed bed is likewise maintained at a constant depth.